1. Field of the Invention
The present invention relates to jet propelled watercraft of the type that generally has a single operator controlling the craft which is propelled by an internal combustion engine having an impeller system for providing a water jet to propel the craft through the water.
These watercrafts are conventionally highly maneuverable, fast, and operate in various bodies of water. The internal combustion engine that drives the watercraft is customarily water cooled and the present invention is directed to an improved water cooling system.
2. Description of the Prior Art
Watercraft of the present type are conventionally driven by internal combustion or diesel engines that are water cooled and the sea water within which the boat is operating is often used to cool the engine. Alternatively, some engines have a sealed fresh water cooling system which in turn is cooled by the sea water employing a heat exchanging unit.
U.S. Pat. No. 5,330,374 discloses a jet boat driving system where sea water is used to propel the boat and also to cool the fresh water cooling system of the engine. U.S. Pat. Nos. 4,552,537 and 3,785,327 show the use of sea water as a coolent as well as the jet propellent of the watercraft. A prior patent that teaches the use of water cooling to cool the oil of a jet boat is U.S. Pat. No. 3,990,424.